Conservation status of threatened fishes in Warner Basin, Oregon

Two federally listed fishes, the Foskett speckled dace and Warner sucker, are endemic to Warner Basin in south central Oregon. The Foskett speckled dace is native only to a single spring in Coleman Valley. A nearby spring was stocked with dace in 1979 and 1980, and now provides a second population. The present numbers of dace probably are at their highest levels since settlement of the region. The Warner sucker historically occurred throughout much of the Warner Valley, but its distribution and abundance have been reduced by construction of reservoirs and irrigation dams and the introduction of predatory game fishes. Lentic habitats have become dominated by introduced fishes, particularly white crappie, black crappie, and brown bullhead. The largest remaining population of Warner suckers occurs in Hart Lake, where successful reproduction was documented but there is no evidence of recruitment to the adult population.     

Haplopappus crispus and H. zionis (Asteradeae): new species from Utah

Two groups of glabrous, narrow-leaved Chrysothamnus viscidiflorus (Asteraceae) are perceived, and appropriate taxonomic combinations are made, i.e., C. v. ssp. viscidiflorus var. stenophyllus and C. v. ssp. axillaris. The two are fairly distinct geographically, and they can be separated by floral morphology. A key to all species of section Chrysothamnus (to which C. viscidiflorus belongs) is given.     

Habitat use and food selection of small mammals near a sagebrush/crested wheatgrass interface in southeastern Idaho

Habitat use and food selection data were collected for deer mice ( Peromyscus maniculatus ), montane voles ( Microtus montanus ), Ord's kangaroo rats ( Dipodomys ordii ), and Townsend's ground squirrels ( Spermophilus townsendii ) near a sagebrush ( Artemisia tridentata )/crested wheatgrass ( Agropyron cristatum ) interface in southeastem Idaho. Significantly more captures occurred in the native sagebrush habitat than in areas planted in crested wheatgrass or in disturbed sites. Crested wheatgrass, a prolific seed producer, still accounted for over 30% of the total captures. Montane voles and Townsend's ground squirrels (during periods of aboveground activity) used the crested wheatgrass habitat throughout the summer, while deer mice and, Ord's kangaroo rats exhibited heavy use after seed set.     

Full-glacial shoreline vegetation during the maximum highstand at Owens Lake, California

Owens Valley, California, was markedly different during the Wisconsin glacial stage from what it is today. Alpine glaciers bounded the Sierra Nevada, and pluvial Owens Lake reached highstands and overflowed its natural basin. We analyzed three layers from two packrat middens, dated to ca 23,000-14,500 yr BP, obtained from Haystack Mountain (1155 m) only 10 m above and Juniperus osteosperma ) and single-needle pinyon pine ( Pinus monophylla ) woodland existed at the site. In the layers dated to ca 17,500 and 16,000 yr BP, macrofossils document the presence of Rocky Mountain juniper ( Juniperus scopulorum ), a species that no longer occurs in California. It is suggested that meltwater from the retreating glacial ice inundated the Owens River Lake chain causing pluvial Owens Lake to reach its highstand. This caused an increase in effective moisture, due to high groundwater, allowing the mesophytic Rocky Mountain juniper to exist at the site.     

Chrysothamnus nauseosus ssp. uintahensis: a stabilized hybrid

Chrysothamnus nauseosus ssp. uintahensis (Asteraceae) is formally described and illustrated. The new subspecies represents stabilized hybrids that most probably have C. nauseosus ssp. hololeucus x C. parryi ssp. attenuatus ancestry. Morphological and anatomical comparisons are made among the putatively related taxa.        

The use of cell free extracts derived from fungal protoplasts in the study of aflatoxin biosynthesis.

A supernatant fraction derived from protoplasts of Aspergillus flavus was shown to be capable of converting both sterigmatocystin and versiconal hemiacetal acetate to aflatoxin B1. Versicolorin A was not converted under the same conditions.     

DNA sequence and analysis of human chromosome 8

The International Human Genome Sequencing Consortium (IHGSC) recently completed a sequence of the human genome. As part of this project, we have focused on chromosome 8. Although some chromosomes exhibit extreme characteristics in terms of length, gene content, repeat content and fraction segmentally duplicated, chromosome 8 is distinctly typical in character, being very close to the genome median in each of these aspects. This work describes a finished sequence and gene catalogue for the chromosome, which represents just over 5% of the euchromatic human genome. A unique feature of the chromosome is a vast region of approximately 15 megabases on distal 8p that appears to have a strikingly high mutation rate, which has accelerated in the hominids relative to other sequenced mammals. This fast-evolving region contains a number of genes related to innate immunity and the nervous system, including loci that appear to be under positive selection--these include the major defensin (DEF) gene cluster and MCPH1, a gene that may have contributed to the evolution of expanded brain size in the great apes. The data from chromosome 8 should allow a better understanding of both normal and disease biology and genome evolution.